Hi Folks; Longtime Lurker/ First-time poster.

Recently picked up a 1998 Cherokee Sport. It's pretty tight...no leaks, wobbles, bad noises, overheating, etc.. It always starts, normally idles fine at ~900 revs, and all onboard systems work fine except the AC, which I don't care much about right now. Had it checked out by a locally-reknowned Jeep/Land Rover shop..had oil changed and coolant flushed. It's my daily driver and runs well.

My Issue and questions;

-->> When driving at sustained highways speeds, (60mph-plus) for any period of time, when you let off the gas...you can feel a slight surging of the motor, revs fluctuate up/down a bit, and the CEL light comes on. Truck continues to run fine. I walked through the procedure for reading any error codes on the odometer, but after doing the 1-thru-9 countdown, no code is displayed and the odometer just returns to displaying mileage.

-->> The CEL light glows amber. If a code was trapped, would it glow red, or is amber the default CEL color on this model year?

-->> If no code displays, is nothing being trapped..as in..there is no actual error condition and the computer is just glitching out? Or is there a more in-depth way to secure the error codes?

--> Beyond any actual error codes, does this sound like an event caused by any set(s) of mechanical conditions that I can look into and systematically walk through as a diagnostic?

Everything from pure speculation to personal prior experience welcome! This is truly an awesome forum...been reading stuff for weeks now.

Best,

Rick M.

 

Try having the codes scanned at a shop, they might not be hard codes but the could be stored as pending in the computer

 

Go to your local auto parts store and have them read the codes. Write down the codes and report back. The codes are stored even if the check engine light isn't on IIRC.

 

Yep. Best move I make was to hit Amazon and get a Code reader.

Also, my 2000 did this when I first bought it. Turned out to be a faulty TPS.

 

Thanks Guys. Is 'TPS" = "Throttle Position Sensor" ?

 

Yes it is.